The French striker completed an eye-watering £36 million move to United from AS Monaco during the summer, for a fee that could rise to £58 million according to clauses [BBC Sport].

Martial’s switch came as something of a surprise due to the fact that the 19-year-old remains unproven and has only completed one full season with AS Monaco.

He managed nine goals in Ligue 1 last term, and is yet to make his France debut. In completing a move to the Premier League, the forward became both the most expensive teenager and the most expensive Frenchman ever.

While Martial will doubtless be delighted at having secured a big-money move to join up with Louis van Gaal, one of his new Premier League rivals has issued a warning.

City defender Mangala has backed Martial to improve quickly, but has noted that the striker’s life will never be the same again.